Also called: bladder
The urinary bladder is a hollow muscular organ in the pelvis that stores urine from the kidneys. Urine enters through the ureters and leaves through the urethra. When full, it rises above the pubic symphysis into the lower abdomen. The detrusor muscle in its wall contracts to empty it.
| Location | Pelvis, behind the pubic symphysis and in front of the rectum in males. |
|---|---|
| Structure | Apex, body, fundus and neck; trigone; detrusor muscle; internal and external urethral sphincters. |
| Function | Stores urine and expels it during micturition. |
| Blood supply | Superior and inferior vesical arteries from the internal iliac artery. |
| Innervation | Parasympathetic pelvic splanchnic nerves (S2-S4) for emptying; sympathetic fibres (T11-L2); somatic pudendal nerve to the external sphincter. |
3D model: BodyParts3D (CC BY 4.0), adult male reference anatomy. Highlighted structure shown with nearby bones for context.
The bladder can typically hold 400 to 600 millilitres, and the urge to void begins at about 150 to 300 millilitres.
The triangular area between the two ureteric openings and the internal urethral orifice.
The detrusor muscle.
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